Low skeletal muscle mass index and all-cause mortality risk in adults: A systematic review and meta-analysis of prospective cohort studies Strong Muscle massMeta-analysisObservational evidenceSystematic review Systematic review & meta-analysis Low skeletal muscle mass index associated with 57% higher all-cause mortality risk (pooled RR 1.57, 95% CI 1.25–1.96) across 16 prospective studies, 81,358 participants Causal status: Associational; prospective cohort evidence, biologically plausible via frailty/functional decline pathway Reliability / bias notes: Heterogeneous SMI definitions across studies; risk magnitude varies substantially by BMI subgroup Wang et al · PLoS One · 2023 · PMID 37285331 Read the study →